Leaching of Vanadium and Chromium from Vanadium-chromium Residue Intensified with H2O2
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摘要: 低价钒和铬难以在碱性条件下直接反应溶出,钠化焙烧会产生较多的废气和废水,钙化焙烧则会带来较大能耗。试验以H2O2作为氧化剂,对钒铬还原渣中钒铬的碱性湿法浸出过程进行强化。研究了Na OH用量、反应温度、H2O2用量、反应时间以及搅拌转速等参数对钒铬浸出率的影响。结果表明:升高反应温度,延长反应时间,可以提高钒和铬的浸出率。在碱性条件下,低价钒比较容易被氧化成高价而溶出,即使氧化剂用量较小时,钒也比较容易被氧化;在H2O2的氧化作用下,钒的浸出率高达94.30%。铬的浸出率随着H2O2用量的增加呈现线性增加的趋势,在合适条件下,铬的浸出率高达90.12%。H2O2作为一种清洁的氧化剂,在反应过程中不会引入杂质,并且能够实现钒和铬的同步高效浸出。该方法具有对环境友好、反应效率高等优势,可以作为一种新型高效氧化技术进行应用。Abstract: Vanadium and chromium in low valence are difficult to be leached in alkaline medium.For vanadium and chromium leaching,roasting with sodium salts might emit some poisonous gas and large amount of waste water,while roasting with calcium salts will consume much more energy.H2O2 as an oxidant was applied to intensify the leaching process of vanadium-chromium residue under alkaline condition.The effect of Na OH dosage,reaction temperature,dosage of H2O2,reaction time and stirring rate on the leaching efficiency of vanadium and chromium was investigated.The results indicate that increasing reaction temperature and extending reaction time can improve the leaching efficiency of vanadium and chromium.Vanadium is more easily to be oxidized and leached out in alkaline medium,even with low dosage of oxidant.The leaching ratio of vanadium is up to 94.30% with addition of H2O2. The leaching ratio of chromium is proportionally increased with increase of H2O2 dosage.Over 90.12% of chromium can be leached out at optimal conditions.H2O2 is a clean oxidant,which realizes an efficient and synchronous extraction of vanadium and chromium without bringing other impurities.This method is environmental-friendly with high reaction efficiency,and it could be applied as a new liquid oxidation technology.
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Key words:
- vanadium-chromium slag /
- vanadium /
- chromium /
- leaching rate /
- oxidation agent /
- H2O2
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